For those who have filed for a US federal trademark registration, you know that once your application has been approved by the Examining Attorney it is then published for opposition by any party that thinks it would be injured by registration of your mark. The opposition period lasts 30 days and it gives trademark rights holders an opportunity to protect against registration of a mark that might narrow the breadth of their rights. But what about the Supplemental Register? Marks that don't qualify for a full registration because they are descriptive or lack some level of distinctiveness can register on the Supplemental Register. So, registration of a such mark on the Supplemental Register is a good option for the applicant as it allows for use of the "®" when the mark is used with the products or services listed in the registration. There are other upsides, plus amendment to the Supplemental Register is not an admission that the mark is not distinctive. So what if someone registers a confusingly similar mark on the Supplemental Register without giving you the chance to oppose that registration? Well, if a third party objects to an application for the Supplemental Register, it must attempt to cancel the registration after it issues. From there it is up to the Trademark Trial and Appeal Board to determine whether the mark remains registered or it is cancelled. That's your option: file a cancellation and lay out the basis for taking the mark off the Supplemental Register.